Patents by Inventor Jie-Fang Li

Jie-Fang Li has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7771846
    Abstract: An ME composite laminate of at least one (1-3) piezo-fiber layer coupled with high-permeability alloy magnetostrictive layers, optionally formed of FeBSiC or equivalent. The composite laminate alternates the (1-3) piezo-fiber and high-permeability alloy magnetostrictive layers in a stacked manner. Optionally, the magnetization direction of the high-permeability alloy magnetostrictive layers and polarization direction of the piezo-fiber layer are an (L-L) arrangement. Optionally, thin film polymer layers are between the (1-3) piezo-fiber layer and high-permeability alloy magnetostrictive layers. Optionally, piezo-electric fibers within the (1-3) piezo-fiber layer are poled by inter-digitated electrodes supported by the thin film polymer, arranged as alternating symmetric longitudinally-poled “push-pull” units.
    Type: Grant
    Filed: August 1, 2007
    Date of Patent: August 10, 2010
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Dwight Viehland, Shuxiang Dong, Jie-Fang Li, Junyi Zhai
  • Publication number: 20080203855
    Abstract: A magneto-electric (ME) gyrator, which is a discrete, passive network element, comprises a laminated composite of piezoelectric and magnetostrictive layers. The ME gyrator approximately meets the following criteria: Vy=??/,, where V is voltage, /is current, and a is a conversion (or gyration) coefficient between voltage and current and non-reciprocity is manifested as a 180° phase shift between open and short circuit (/,F) conditions, and =* 1 (Ib) where c0 is the speed of light in vacuum, ?e?is the effective relative dielectric constant, and ?c?is the effect?ive relative permeability.
    Type: Application
    Filed: June 5, 2006
    Publication date: August 28, 2008
    Inventors: Dwight D. Viehland, Jie-Fang Li, Mirza I. Bichurin
  • Publication number: 20080193780
    Abstract: An ME composite laminate of at least one (1-3) piezo-fiber layer coupled with high-permeability alloy magnetostrictive layers, optionally formed of FeBSiC or equivalent. The composite laminate alternates the (1-3) piezo-fiber and high-permeability alloy magnetostrictive layers in a stacked manner. Optionally, the magnetization direction of the high-permeability alloy magnetostrictive layers and polarization direction of the piezo-fiber layer are an (L-L) arrangement. Optionally, thin film polymer layers are between the (1-3) piezo-fiber layer and high-permeability alloy magnetostrictive layers. Optionally, piezo-electric fibers within the (1-3) piezo-fiber layer are poled by inter-digitated electrodes supported by the thin film polymer, arranged as alternating symmetric longitudinally-poled “push-pull” units.
    Type: Application
    Filed: August 1, 2007
    Publication date: August 14, 2008
    Inventors: Dwight Viehland, Shuxiang Dong, Jie-Fang Li, Junyi Zhai
  • Publication number: 20060279171
    Abstract: A magneto-electric (ME) gyrator, which is a discrete, passive network element, comprises a laminated composite of piezoelectric and magnetostrictive layers. The ME gyrator approximately meets the following criteria: V1=??I2, V2=?I1??(1a) where V is voltage, I is current, and ? is a conversion (or gyration) coefficient between voltage and current and non-reciprocity is manifested as a 180° phase shift between open and short circuit (I,V) conditions, and ? ? ? ? c 0 ? eff ? ? eff ? 1 ( 1 ? b ) where c0 is the speed of light in vacuum, ?eff is the effective relative dielectric constant, and ?eff is the effective relative permeability.
    Type: Application
    Filed: June 2, 2006
    Publication date: December 14, 2006
    Inventors: Dwight Viehland, Jie-Fang Li, Mirza Bichurin
  • Patent number: 7023206
    Abstract: A magnetoelectric magnetic field sensor has one or more laminated magnetostrictive layers and piezoelectric layers. The magnetostrictive layers are magnetized by a bias magnetic field in a longitudinal, in-plane direction. The piezoelectric layers can be poled in the longitudinal direction or perpendicular direction. The longitudinal magnetization of the magnetostrictive layers provides greatly increased sensitivity at lower bias fields compared to other magnetoelectric sensors. Perpendicular poling of the piezoelectric layers tends to provide higher sensitivity at lower detection frequency (e.g. less than 1 Hz). Longitudinal poling tends to provide higher sensitivity at high detection frequency (e.g. above 10 Hz). Also included are embodiments having relative thicknesses for the magnetostrictive layers that are optimized for sensitivity. Equations are provided for calculating the best relative thickness for the magnetostrictive layer for maximum sensitivity.
    Type: Grant
    Filed: October 20, 2003
    Date of Patent: April 4, 2006
    Assignee: Virginia Tech Intellectual Properties, Inc.
    Inventors: Dwight Viehland, Shu-Xiang Dong, Jie-Fang Li
  • Publication number: 20040126620
    Abstract: A magnetoelectric magnetic field sensor has one or more laminated magnetostrictive layers and piezoelectric layers. The magnetostrictive layers are magnetized by a bias magnetic field in a longitudinal, in-plane direction. The piezoelectric layers can be poled in the longitudinal direction or perpendicular direction. The longitudinal magnetization of the magnetostrictive layers provides greatly increased sensitivity at lower bias fields compared to other magnetoelectric sensors. Perpendicular poling of the piezoelectric layers tends to provide higher sensitivity at lower detection frequency (e.g. less than 1 Hz). Longitudinal poling tends to provide higher sensitivity at high detection frequency (e.g. above 10 Hz). Also included are embodiments having relative thicknesses for the magnetostrictive layers that are optimized for sensitivity. Equations are provided for calculating the best relative thickness for the magnetostrictive layer for maximum sensitivity.
    Type: Application
    Filed: October 20, 2003
    Publication date: July 1, 2004
    Inventors: Dwight Viehland, Shu-Xiang Dong, Jie-Fang Li